Field of Endeavour
The device described herein generally relates to the field of removal of metal fitting bands or rings from the outside surface of plastic pipes.
Description of Related Art
In recent years has become preferred in the construction industry, especially in plumbing application. Plastic tubing is replacing traditional metal piping in many plumbing, piping, and conduit applications. Plastic tubing provides the advantages of being inexpensive to manufacture, lightweight for construction and shipping purposes, and easy to install due to its pliable and ductile properties. Plastic piping is referenced with different terminology, such as piping, tubing, hose, or other like terms.
A common type of plastic tubing is made of cross-linked polyethylene, commonly abbreviated as “PEX.” PEX tubing joints rely on clamps to form a tight seal to prevent leakage. Some of the more common clamps include cinch clamps, crimp rings, band clamps. These clamps and rings are commonly made of bands of metal, such as copper, brass, or some other relatively soft metal.
There are times when a joint must be removed or detached, such as to change a tubing configuration or to correct a misaligned joint or other fabrication error. Removing the metal clamps from the tubing is difficult because the hard, rigid metal bands of the clamp overlay the relatively soft plastic tubing. In many instances, removal of the metal bands causes severe destruction to the tubing, rendering it inoperable for subsequent use. For example, a common cinch clamp removal tool is a rotary tool with a rotary blade, such as the rotary tools made by Dremel® rotary tools made by Robert Bosch Tool Corporation. These rotary tools comprise a circular blade spinning at a high rate to cut through the metal band. However, since the metal band is clamped tightly to the plastic tubing, the band is seated snugly to the surface of the tubing. Cutting the band often results in over penetration by the cutting tool, thus causing damage or even a cut in the plastic tubing.
Other prior art devices use a clamping-style hand held tool to make a cut in the metal band. However, since the soft plastic tubing lies under the metal band, use of these tools often result in crushing the tubing without the cutting tool fully penetrating the metal band. As a result, the plastic tubing is destructively crushed, and the metal band becomes mangled, but in tact.
Other prior art devices, such as the device depicted in U.S. Pat. No. 6,769,181, are oriented to make tangential or off center cuts on the metal band, thereby reducing the magnitude of the crushing force on the underlying plastic tubing. However, these devices are difficult to operate because they are plier-style clamping devices with an open face. In use, it is very difficult to align the cutting blade at a tangential or substantially off center orientation to the metal band and apply the appropriate cutting force without the pipe or tubing slipping out of the open face.
Therefore, what is needed is a hand-held tool for cutting a metal clamping band off of plastic tubing in a manner that is easy and safe to operate, and that provides consistent and effective results without damaging the plastic tubing.